The incident happened at a shop in Limehurst Square, in Duston off Limestone Road, on March 28 between 7.55pm and 8.15pm, when three males entered the shop wearing masks, Northamptonshire Police today revealed.

One of them threatened the assistant with a meat cleaver and demanded cash. They also stole cigarettes, alcohol and a mobile phone before making off on foot.

A spokeswoman for Northamptonshire Police said: "The first offender is described as a white male wearing a black hoodie, red cap and grey jeans.